High Frequency Reciprocating Test Rig Research Articles

EVALUATION OF THE LUBRICATION OF ETHYL OLEATE AND ETHYL OCTANOATE AS GASOLINE ADDITIVE

The present study assesses the effects of ethyl octanoate and ethyl oleate on the gasoline lubricity. Samples of gasoline fuel were prepared with different amounts of esters (0%, 2.5%, 5%, 10%, and 15%) and then evaluated. The lubricity tests were carried out using a High Frequency Reciprocating Test Rig (HFRR) equipment. The Wear Scar Diameter (WSD) values decreased as ester proportions increased in the samples. The percentage of lubricant film presented values above 85% for formulations with 10% and 15% ester concentration. Coefficient of friction values showed a similar behavior, they decreased as the esters fractions have increased. Results demonstrate that the esters when added to gasoline can improve the fuel lubricity.

Assessment on Tribological Characteristics of Waste Ayurvedic Oil Biodiesel Blends using High-Frequency Reciprocating Rig Tribometer

In general the components of the engine create more wear and friction in metal to metal contact surface, when the engine runs with petroleum based fossil fuel. This may damage the mating parts especially cylinder liner and piston ring, this may lead engine life reduction, increase of service cost. The biodiesel will give good lubrication property than the petroleum based fossil fuels. Basically, the researchers are mainly focusing on waste management system and its processes in the way of reduction in the virgin feed stocks used as a alternate fuel. This study dealt to investigate the tribological property of Waste Ayurvedic Oil (WAO) biodiesel blends by comparing with diesel fuel to improve fuel lubricity by using High Frequency Reciprocating Test Rig. The experimental investigation was conducted with load: 10N, frequency: 50Hz, stroke length: 15mm, time: 75min, temperature: 60°C. From the test results it is concluded that the range of blending of biodiesel from 10%, 15% and 20% of WAO with diesel fuel will results remarkable amount of improvement in the lubricity. Coefficient of friction and wear has been decreased with the increases percentages of biodiesel in blends. The WAO20 gives better reduction values in terms of co-efficient of friction, wear depth and frictional force than other WAO blended fuel and diesel fuel. The tested surfaces of cylinder liner were investigated using Scanning Electron Microscope (SEM) and atomic force microscopic analysis (AFM). The image shows a better impact and less wear scars for the WAO blended fuels than diesel fuel.

Effect of bio-lubricant on wear characteristics of cylinder liner-piston ring and cam-tappet combination in simulated environment

The present investigation focuses on need of bio-based lubricants which are biodegradable and environmental-friendly along with improved oxidative stability. The global demand for lubricants is expected to increase as the demand for engine oil for new motor vehicle increases with the increase in number of vehicles. The depleting nature of mineral oils and its adverse impacts on environment has raised the attention of scientists towards the utilisation of renewable bio-based lubricants. The increased environmental awareness is a primary driving force for the new technological developments. In the present study, waste cooking oil (WCO) biodiesel is used as a feedstock for blending with lubricating oil as it is the economical source for the production of biodiesel. WCO was chemically modified by transesterification process. The effect of friction and wear behaviour on performance of cylinder liner-piston and cam-tappet in valve train under lubricating condition has been studied using high frequency reciprocating test rig (HFRR) and pin on disc tester (POD). In addition, the investigations of lubricant variants after the test were also carried out with analytical ferrography to analyse the wear debris in the lubricants. The 10% blending of SAE20W40 with WCO biodiesel exhibits improved results in terms of coefficient of friction and wear scar diameter (WSD).

Preparation and evaluation of Jatropha curcas based catalyst and functionalized blend components for low sulfur diesel fuel

A promising biochar-based catalyst was successfully developed from Jatropha curcas hull and de-oiled meal by incomplete carbonization and subsequent sulfonation. The catalysts were employed to produce functionalized blend components for low sulfur diesel. The catalysts were characterized by XRD, TG-DSC, BET, FT-IR and SEM. The characterization results revealed that the catalysts consisted of irregular, porous framework bearing abundant functional groups (–SO3H). The catalysts demonstrated high catalytic activity in transesterification, especially in esterification of free fatty acid (FFA). The superior catalytic activity was performed owing to high active sites density, large pores and loose irregular network of the catalysts, which facilitated mass transport of the reactant molecules and further enhanced the active sites accessibility. And the catalyst is fairly stable after five reaction recycles. The lubricating performance of the product was evaluated by high-frequency reciprocating test rig (HFRR). The findings indicated that methyl esters derived from Jatropha curcas oil were efficient enough to use as lubrication blend components and the average wear scar diameter (WSD) values of the sample fuel decreased progressively with the increasing of additive concentration.

Upgrading the lubricity of bio-oil via homogeneous catalytic esterification under vacuum distillation conditions

In order to accelerate the application of bio-oil in the internal combustion engines, homogeneous catalytic esterification technology under vacuum distillation conditions was used to upgrade the crude bio-oil. The lubricities of the crude bio-oil (BO) and refined bio-oil with homogeneous catalytic esterification (RBOhce) or refined bio-oil without catalyst but with distillation operation (RBOwc) were evaluated by a high frequency reciprocating test rig according to the ASTM D 6079 standard. The basic physiochemical properties and components of the bio-oils were analyzed. The surface morphology, contents and chemical valence of active elements on the worn surfaces were investigated by scanning electron microscopy, energy dispersive spectroscopy and X-ray photoelectron spectroscopy, respectively. The results show that RBOhce has better lubricities than those of BO, but RBOwc has worse lubricities than those of BO. The tribological mechanisms of the bio-oils are attributed to the combined actions of lubricating films and factors that will break the film. Compared with BO, plenty of phenols in RBOwc results in corrosion of the substrate and destroys the integrity of the lubricating films, which is responsible for its corrosive wear. However, more esters and alkanes in RBOhce contribute to forming a complete boundary lubricating film on the rubbed surfaces which result in its excellent antifriction and antiwear properties.

Investigation on the Potential of Dextrose, Sucrose and Cellulose Dodecenylsuccinate Esters as Lubricity Additive

As a consequence of the environmental issues and the increasing global demand of the lubricants, we need to have the sustainable raw material sources not only for the lube base oil but also for additives. In view of this, we have synthesized the dodecenylsuccinate (DDSA) ester of dextrose (sample 1), sucrose (sample 2) and cellulose (sample 6) with almost same degree of substitution (DS ~2.0). The lubricity was observed for these synthesized samples in n-decane which was taken as lubricant reference base fluid. The lubricity tests were carried out as per the ASTM D6079 using high frequency reciprocating test rig. It was observed that the dextrose-DDSA ester shows good lubricity properties in comparison to sucrose and cellulose. 1 % sucrose-DDSA in n-decane has decreased the value of wear scar diameter from 800 to 515 µm while the values for sucrose-DDSA and cellulose-DDSA were found to be 565 and 590 µm respectively. Further, to see the effect of varying DS over the lubricity in the case of cellulose-DDSA esters, the four cellulose ester samples (sample 3–6) with varying DS (0.68, 0.95, 1.43 and 2.03) were prepared and evaluated. It was also observed that the lubricity increases with the increasing DS value in cellulose-DDSA esters.

Residual stresses, interfacial adhesion and tribological properties of MoN/Cu composite coatings

Ceramic thin film coatings, such as MoN/Cu, are attractive for engine applications due to their low friction, high hardness and high wear resistance. However, there is a need to establish a reliable connection between the deposition parameters of the thin film and its tribological performance. In this study, two coating compositions, MoN and MoN with Cu were deposited on H-13 tool steel substrates in order to correlate compositional variables that result from processing to their respective tribological properties. The efficacy of the coating in protecting surfaces is highly dependent on its adhesion to the substrate and its tribological properties. Residual stresses resulting from the coating deposition were evaluated using an X-ray microprobe. Scratch testing was performed to measure the coating adhesion energy, and the wear rate was determined using a ball-on-flat contact configuration on a high frequency reciprocating test rig. It was observed that coatings with lower copper content performed better in the wear test and exhibited higher coating adhesion energy. A primary wear damage mechanism was coating removal by delamination and spallation, which is related to the adhesion energy. Since coating processing variables determine the structure and properties, and hence affect the tribological properties of these MoN based coatings, these parameters can be used to optimize coating composition for enhanced tribological performance.

On the Corrosion Behavior of Refined Bio-Oil during Rubbing Process

The corrosion behavior during friction of refined bio-oil by distillation process was evaluated by high frequency reciprocating test rig. Both scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) were used to investigate the morphology and active elements contents on the rubbed surface on steel disk. The chemical structures of the oils and the topography and surface roughness of the wear scar were also studied by FTIR and surface roughness tester as well, respectively. The experimental results showed that corrosion behavior of bio-oil was improved after refining since the wear depth was 3.75µm and the worn surface roughness was 0.172µm, while they were 12.5µm and 0.217µm before refining. It was concluded that corrosion degree of worn surface was decreased after the bio-oil was refined, which was ascribed to the decrease of the acidic component content after the refining process.

Characterization of the lubricity of bio-oil/diesel fuel blends by high frequency reciprocating test rig

Abstract The diesel fuel was mixed with the rice husk bio-oil using some emulsifiers based on the theory of Hydrophile-Lipophile Balance (HLB). The lubricity of the bio-oil/diesel fuel blend was studied on a High Frequency Reciprocating Test Rig (HFRR) according to ASTM D 6079–2004. The microscopic topography and chemical composition on the worn surface were analyzed respectively using scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The profile and surface roughness of the rubbed trace were measured using a profilometer. The chemical group and composition were studied by a Fourier transform infrared spectrometry (FTIR). The results showed that the lubrication ability of the present fuel blend was better than that of the Chinese conventional diesel fuel (number zero). However, the anti-corrosion and anti-wear properties of the fuel blend were not satisfactory in comparison with those of conventional diesel fuel.

Design of Functionalized PAMA Viscosity Modifiers to Reduce Friction and Wear in Lubricating Oils

Abstract Polyalkylmethacrylates (PAMAs) are widely used as both viscosity index improvers and dispersant boosters in engine, hydraulic, and transmission oils. Since they are employed in a relatively high concentration in these roles, it is desirable that they be able to enhance other characteristics of a lubricant and, in particular, its boundary lubricating properties. A series of functionalized PAMAs have been synthesized that can adsorb from oil solution onto rubbing surfaces to produce thick boundary films. These films enhance lubricant film formation in slow speed and high temperature conditions and thus make a significant contribution to their lubricating ability. The current paper describes a systematic study of the influence of functionalized PAMAs on boundary lubrication performance. The high frequency reciprocating test rig (HFRR) was applied to investigate friction and wear under pure sliding. A new test method has been developed which allows wear to be monitored in a rolling and sliding contact based on the mini traction machine (MTM). This, in combination with other tests, is employed to investigate the influence of polymer architecture, functionality, concentration and molecular weight on friction and wear in a range of lubricant formulations. This enables the tailored design of polymers which offer low friction and wear properties.

Effect of Carbon Coating on Scuffing Performance in Diesel Fuels

Low-sulfur and low-aromatic diesel fuels are being introduced in order to reduce various types of emissions in diesel engines to levels in compliance with current and impending U.S. federal regulations. The low lubricity of these fuels, however, poses major reliability and durability problem for fuel injection components that depend on diesel fuel for their lubrication. In the present study, the authors evaluated the scuff resistance of surfaces in regular diesel fuel containing 500 ppm sulfur and in Fischer-Tropsch synthetic diesel fuel containing no sulfur or aromatics. Tests were conducted with the high frequency reciprocating test rig (HFRR) using 52100 steel balls and H-13 tool-steel flats with and without Argonne's special carbon coatings. Test results showed that the sulfur-containing fuels have about 20% higher scuffing resistance than does fuel without sulfur. The presence of the carbon coating on the flat increased scuffing resistance in both regular and synthetic fuels by about ten times, as measured by the contact severity index at scuffing. Coating removal was observed to be a necessary, but not sufficient condition for scuffing failure in tests conducted with coated surfaces. The loss of coating from the surface occurred by the two distinct mechanisms of spalling and wear. Presented as a Society of Tribologists and Lubrication Engineers Paper at the ASME/STLE Tribology Conference in Seattle, Washington, October 1–4, 2000

A Preliminary Evaluation of Esters of Monocarboxylic Fatty Acid on the Lubrication Properties of Diesel Fuel

This paper assesses the impact of esters of monocarboxylic fatty acids, on the lubrication properties of ultra-low-sulfur diesel fuels. Seven esters were used as lubricating additives on a matrix of eight fuels, at five different concentrations of 50, 100, 500, 750, and 1000 ppm. Tribological experiments carried out on the high-frequency reciprocating test rig (HFRR) showed that the effective concentration of the additives was 500 ppm or higher.